Plants' ability to respond to light is crucial for their survival. Recent evidence implicating brassinosteroids (BRs) in the light response has made the identification of brassinosteroid response components of great interest. Seedlings unable to synthesize BRs develop as light-grown plants even when grown in darkness. Moreover, these mutants reveal a significant role for BRs throughout development. Traditional screens attempting to identify components of the BR response and signaling pathway have been hampered by failure to uncover mutations in all but one gene, BRI1. Several explanations for why only one gene was identified in these screens are possible. Two of the most likely are that the genes required for BR response are involved in other pathways (thus yielding phenotypes distinct from BR synthetic mutants) and/or that these genes are redundant or essential for viability. I will use novel approaches to circumvent these obstacles and identify new components of BR signaling. In the first of these approaches, quantitative trait loci analysis on disparate Arabidopsis ecotypes will allow me to first localize and then clone new BR response elements. Secondly, characterization of BR: auxin synergy in Arabidopsis will define a new niche of BR research. This striking example of communication between hormone pathways presents an opportunity to better understand the signaling of each hormone alone as well as the nodes of intersection between them.